/*
 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package javax.lang.model.element;

import java.util.List;
import javax.lang.model.type.*;
import javax.lang.model.util.*;

/**
 * Represents a class or interface program element.  Provides access
 * to information about the type and its members.  Note that an enum
 * type is a kind of class and an annotation type is a kind of
 * interface.
 *
 * <p> <a name="ELEM_VS_TYPE"></a>
 * While a {@code TypeElement} represents a class or interface
 * <i>element</i>, a {@link DeclaredType} represents a class
 * or interface <i>type</i>, the latter being a use
 * (or <i>invocation</i>) of the former.
 * The distinction is most apparent with generic types,
 * for which a single element can define a whole
 * family of types.  For example, the element
 * {@code java.util.Set} corresponds to the parameterized types
 * {@code java.util.Set<String>} and {@code java.util.Set<Number>}
 * (and many others), and to the raw type {@code java.util.Set}.
 *
 * <p> Each method of this interface that returns a list of elements
 * will return them in the order that is natural for the underlying
 * source of program information.  For example, if the underlying
 * source of information is Java source code, then the elements will be
 * returned in source code order.
 *
 * @author Joseph D. Darcy
 * @author Scott Seligman
 * @author Peter von der Ah&eacute;
 * @see DeclaredType
 * @since 1.6
 */
public interface TypeElement extends Element, Parameterizable, QualifiedNameable {

  /**
   * Returns the fields, methods, constructors, and member types
   * that are directly declared in this class or interface.
   *
   * This includes any (implicit) default constructor and
   * the implicit {@code values} and {@code valueOf} methods of an
   * enum type.
   *
   * <p> Note that as a particular instance of the {@linkplain
   * javax.lang.model.element general accuracy requirements} and the
   * ordering behavior required of this interface, the list of
   * enclosed elements will be returned in the natural order for the
   * originating source of information about the type.  For example,
   * if the information about the type is originating from a source
   * file, the elements will be returned in source code order.
   * (However, in that case the the ordering of synthesized
   * elements, such as a default constructor, is not specified.)
   *
   * @return the enclosed elements in proper order, or an empty list if none
   */
  @Override
  List<? extends Element> getEnclosedElements();

  /**
   * Returns the <i>nesting kind</i> of this type element.
   *
   * @return the nesting kind of this type element
   */
  NestingKind getNestingKind();

  /**
   * Returns the fully qualified name of this type element.
   * More precisely, it returns the <i>canonical</i> name.
   * For local and anonymous classes, which do not have canonical names,
   * an empty name is returned.
   *
   * <p>The name of a generic type does not include any reference
   * to its formal type parameters.
   * For example, the fully qualified name of the interface
   * {@code java.util.Set<E>} is "{@code java.util.Set}".
   * Nested types use "{@code .}" as a separator, as in
   * "{@code java.util.Map.Entry}".
   *
   * @return the fully qualified name of this class or interface, or an empty name if none
   * @jls 6.7 Fully Qualified Names and Canonical Names
   * @see Elements#getBinaryName
   */
  Name getQualifiedName();

  /**
   * Returns the simple name of this type element.
   *
   * For an anonymous class, an empty name is returned.
   *
   * @return the simple name of this class or interface, an empty name for an anonymous class
   */
  @Override
  Name getSimpleName();

  /**
   * Returns the direct superclass of this type element.
   * If this type element represents an interface or the class
   * {@code java.lang.Object}, then a {@link NoType}
   * with kind {@link TypeKind#NONE NONE} is returned.
   *
   * @return the direct superclass, or a {@code NoType} if there is none
   */
  TypeMirror getSuperclass();

  /**
   * Returns the interface types directly implemented by this class
   * or extended by this interface.
   *
   * @return the interface types directly implemented by this class or extended by this interface,
   * or an empty list if there are none
   */
  List<? extends TypeMirror> getInterfaces();

  /**
   * Returns the formal type parameters of this type element
   * in declaration order.
   *
   * @return the formal type parameters, or an empty list if there are none
   */
  List<? extends TypeParameterElement> getTypeParameters();

  /**
   * Returns the package of a top-level type and returns the
   * immediately lexically enclosing element for a {@linkplain
   * NestingKind#isNested nested} type.
   *
   * @return the package of a top-level type, the immediately lexically enclosing element for a
   * nested type
   */
  @Override
  Element getEnclosingElement();
}
